Bogacko [bɔˈɡat͡skɔ] (German: Bogatzko: 1938-45: Rainfeld) is a village in the administrative district of Gmina Giżycko, within Giżycko County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 8 kilometres (5 mi) west of Giżycko and 81 km (50 mi) east of the regional capital Olsztyn.
Before 1945 the area was part of Germany (East Prussia). Following World War II the native German populace was expelled and replaced by Poles.
Coordinates: 54°3′N 21°39′E / 54.050°N 21.650°E